This commentary raises three questions about the target article: What are pointers or deictic devices? Why insist on deictic codes for cognition rather than deixis simpliciter? And in what sense is cognition embodied, on this view?

The majority of commentators agree that the time to focus on embodiment has arrived and that the disembodied approach that was taken from the birth of artificial intelligence is unlikely to provide a satisfactory account of the special features of human intelligence. In our Response, we begin by addressing the general comments and criticisms directed at the emerging enterprise of deictic and embodied cognition. In subsequent sections we examine the topics that constitute the core of the commentaries: embodiment mechanisms, dorsal and ventral visual processing, eye movements, and learning.

Express saccade experiments imply that attention shifts take time. We extend this result with new experiments on manual reaction times. Reaction to a cued target is always slower than reaction to an uncued control, even when the cue is correct, if control trials are blocked to prevent interference from cued trials. Attention functions not to speed response, but to prevent responses at irrelevant locations.

Inappropriate saccades are prevented by fixation and by voluntary attention. The fixation system inhibits the saccade system. Like monkeys without a fixation system, humans with a weak fixation system produce many express saccades and cannot suppress prosaccades in an antisaccade task. With permanent attention to a peripheral location only a few express saccades to a stimulus at this location can be elicited: the sustained component of attention acts like fixation. When attention is captured by a precue, more express saccades are obtained: the stimulus-driven component of attention facilitates saccade generation. If the cue correctly indicates the direction for an antisaccade error rate and latencies are increased.

Motor processes cannot be modeled by a single (unified) model. Instead, a number of models at different levels of description are needed. The concepts of control and control variable only make sense at the functional level. A clear distinction must be made between external models and internal models. General Systems Theory provides the framework for a proper treatment of these issues.

The basic concepts of motor control formulated in our target article were derived from specific experiments, a fact which is disregarded in Dalenoort's comments. A purely academic approach to motor control may not result in a clearer understanding of control concepts.

In many base rate studies, a judgment is required for which the base rates are relevant, and subjects do not use them. It is inferred that the base rates are ignored; I question this inference. Second, I argue that the base rate fallacy is not less significant for what it reveals about human reasoning, if it occurs less frequently than has been alleged.

This commentary is in agreement with the thrust of Koehler's target article. The issue I deal with is whether a Bayesian framework represents an adequate general normative framework for deciding the rationality of lay judgments, even when it can be unambiguously applied.

The meaning of an experimental result depends on the experiment's conceptual backdrop, particularly its null hypothesis. This observation provides the basis for a functional interpretation of belief in the base rate fallacy. On this interpretation, if the base rate fallacy is to be labelled a “myth,” then it should be recognized that this label is not necessarily a disparaging one.

Koehler's (1996t) target article raised, and various commentators discussed, two issues that seem far separated but actually have a great deal in common. These are the value of “ecologically valid” research and the effect of direct experience on base-rate usage. Koehler discussed the former as a methodological issue and the latter as a normative one, and no commentator chose to incorporate them, but directly experienced base rates are a good example of ecologically valid research. The state of the literature with regard to directly experienced base rates is reviewed, and the emerging perception, that direct experience has a profound Bayesian effect on base-rate usage, is rejected.

In base rate problems the estimated probability must equal the base rate only where random sampling is assumed. Otherwise there is uncertainty over and above that which can be included in any probability model and inductive inference is involved. Subjects should use base rates to the extent that the problem suggests a simple random sampling model.

Most tasks used to demonstrate the base rate fallacy are ambiguous about the independence of the data. The removal of such ambiguities from the texts (by means of a clear reference class for the probabilities) is a necessary condition and has a considerable effect on the use of the base rate in classical probabilistic tasks. Some comments are offered on the frequentist phrasing of such and, more generally, their ecological validity.

Subjects are reported as being somewhat Bayesian, but as violating the normative ideal on occasion. To abjure probability altogether is difficult. To use Bayes' Theorem scrupulously when weighing evidence can incur costs without corresponding benefits. The subjects' evident nuanced probabilism appears both realistic and reasonable.

I agree with Gibbs that the message of the base rate literature reads differently depending on which null hypothesis is used to frame the issue. But I argue that the normative null hypothesis, H0: “People use base rates in a Bayesian manner,” is no longer appropriate. I also challenge Adler's distinction between unused and ignored base rates, and criticize Goodie's reluctance to shift research attention to the field. Macchi's arguments about textual ambiguities in traditional base rate problems suggest that empirical testing is needed to tease apart the effects of problem clarification and problem framing. Macdonald's, Fletcher's and Snow's skepticism about the value of Bayesian methods in real world judgment tasks is treated as a challenge for the next generation of empirical base rate studies.